N. H. Casey

• DSc (Agric) Animal Science
• University of Pretoria

Thyroid hormones are critical for the growth, development and maintenance of the body. The review aims to consider the sources of bromide, elucidate the potential effects that bromide could have on the functioning of thyroid hormone and to present the risks of exposure and ingestion of bromide to livestock production.

Thyroid hormones are critical for the growth, development and maintenance of the body. The review aims to consider the sources of bromide, elucidate the potential effects that bromide could have on the functioning of thyroid hormone and to present the risks of exposure and ingestion of bromide to livestock production.

Thyroid hormones are critical for the growth, development and maintenance of the body. The review aims to elucidate the potential effects that bromide could have on the functioning of thyroid hormone and to present the risks of exposure and ingestion of bromide to livestock production.

Thyroid hormone is a component of a network of hormones that include the pituitary hormones, thyroid stimulating hormone and growth hormone, critical for the growth, development and maintenance of the body. The aim of this review is to elucidate the potential effects that bromide could have on the functioning of thyroid hormone and to present the r...

This paper explores the possible mechanisms of bromide as a thyroid hormone disruptor in the animal body.

The agricultural product market is changing from a producer-orientated to a more consumer-orientated market. Consumer rely on the classification system within the red meat types. Different red meat types and carcass classifications influence the prices of red meat. This study was conducted to determine the price dynamics of different red meat carca...

The hypothesis was that owing to their high bioavailability, zinc oxide nanoparticles (NanoZnO) can effectively replace (Zn) salts and reduce Zn excretion with faeces. The objective of this study was to investigate the effects of NanoZnO on the development of chicken embryos, the growth of broiler chickens, and Zn excretion with faeces. At day 1 of...

A look at the possible consequences of bromide exposure on poultry production, where pre- and post-hatch wellbeing and performance are key production targets.

Many regions across South Africa are dependent on groundwater as the only water source for livestock watering and domestic use. This paper presents an analysis of 350 water samples from collated data of 5 reports published between 2001 and 2016 that show the vast range of 0-132.68 mg/L bromide (Br−) present in South African groundwater. It further...

Many regions across South Africa are dependent on groundwater as the only water source for livestock watering and domestic use. This paper presents an analysis of 350 water samples from collated data of 5 reports published between 2001 and 2016 that show the vast range of 0–132.68 mg/L bromide (Br−) present in South African groundwater. It further...

The effect of bromide on the physiology of production animals and the negative implications of exposure to livestock productivity.

Bromide (Br-) concentrations (mg/L) in groundwater range from no observed adverse effect levels (NOAEL), which is considered safe, and increase to constituent of concern (COC) when the concentrations approach the recommended maximum levels for safety, and to potentially hazardous chemical constituent when the concentrations exceed the recommended s...

Ostriches are susceptible to Newcastle disease virus (NDV); farmed ostriches are inoculated against the infection. The research aimed to establish humoral responses of ostrich chicks to L-carnitine to improve immunity against NDV. A dietary supplement of L-carnitine was administered to chicks from day-old to 81 days; sera antibody titre was the hum...

This paper presents a model to quantify total greenhouse gas (GHG) emissions from dairy farms. The model, which is based on a whole farm management approach, accounts for the variability that occurs in GHG emissions among farm production and management practices. The variation is accommodated in six dairy farm management systems (FMS), which broadl...

Twenty-six-week-old laying hens (90 Lohmann Classic Brown) received dietary treatments containing canola and linseed oil at 2% inclusion levels and a control diet for 21 days. The 2% dietary linseed oil, which had higher total polyunsaturated fatty acids (ΣPUFA) and linolenic fatty acid contents, resulted in higher liver malondialdehyde and wider v...

The study pursued the hypothesis that bromine (Br) in drinking water at levels > 0.01 mg Br/L may have detrimental effects on the liver, kidneys and thyroid and the thyroid hormones T3 and T4 and that iodine (I) may alleviate the potential hazardous effect of Br. The research was done with mixed Ross broiler chickens over a 42-day post-hatch growth...

• Monitoring and managing the quality of water for livestock systems is an essential consideration to obtain optimal production, maximize the use of a precious natural resource, and minimize the risk of adverse effects that can limit production. Inorganic constituents in water may be from industry (manufacturing, mining, and agriculture) but are mo...

This book focuses on the most important areas of goat meat production. It is divided into 15 chapters discussing the role of genetics, breeding, reproduction and nutrition in producing good quality, profitable goat meat. The mineral, amino acid and fatty acid composition of goat meat is also addressed, along with a discussion of its nutritive value...

A thorough understanding of growth and development in goats and the factors that affect these processes is important, because it affects the efficiency of production and it has a direct bearing on product quality. Although the use of growth promotants or molecules that change the effi-ciency of growth are not generally employed in goats, other more...

The study tested the performance of intact male pigs from a selected genetic line subjected to differing feeding regimens and penning conditions. The trial was a 2 x 3 x 2 x 3 factorial design, consisting of winter and summer periods, three sire lines, two diets and three feeding regimens. The pigs were intact males grown over three phases, starter...

The objective was to determine the growth responses of Black Neck ostrich chicks to different dietary levels of L-carnitine in pre-starter diets. Thirty-two day-old ostrich chicks were randomly divided into four treatments with four replicates, each containing two chicks. All birds received the same basal diet supplemented with 0 (T0, control), 125...

Water quality constituents ingested through drinking water can affect the animal's physiology negatively and, through bioaccumulation in tissues, pose a biohazard to consumers. The study evaluated the effectiveness of a total dissolved solid (TDS) treatment as a possible alleviator of the accumulation of potentially hazardous chemical constituents...

Commercialisation of animal agriculture changed the phenotype and production characteristics of livestock. The sigmoidal growth curve and sequence of physiological events remained virtually unchanged, but the rate and extent of these processes increased remarkably. Physiological limits to growth are apparent in species selected for accelerated grow...

Intellectual capital (IC) is a key concept to sustaining a global livestock industry. Accumulated IC in animal science has contributed to successfully developing an efficient global industry, but that has come at a cost to the environment. The challenge is to develop IC to address the negative aspects of the livestock industry, yet continue the adv...

Managing goat production for meat quality is a deliberate, active process that reaches from conception to consumption. The concept of quality in meat is universal, being wholesome, nutritious and palatable. Goat meat is a product of many different production systems from widely varying environments, nutritional regimes and genotypes. The physical,...

Bonsmara type steers were used to determine the effect of dietary zilpaterol hydrochloride (ZH) in combination with different dietary crude protein (CP) levels (100, 120 and 140 g CP/kg) on growth performance and meat quality. Treatment groups (T) consisted of 12 steers each. T1 - 100 g CP/kg + 0.15 mg ZH/kg live weight (LW); T2 - 120 g CP/kg + 0.1...

Levels of bromine (Br) in groundwater that exceeded guideline concentrations of 0.01 mg/L prompted the investigation of the effect Br and iodine (I) in drinking water on the production parameters of broilers. The research was done over a 42-day growth period, post-hatch, in which the trial design was: Control: 0 mg Br/L and 0 mg I/L; 1 mg Br/L and...

The aim of this research was to study the effect of high-maize diets and pelleting on the accumulation of lutein pigments and appearance of the subcutaneous fat in Dorper and SA Mutton Merino wethers. High and medium energy maize diets were fed to Dorper and SA Mutton Merino wethers from an initial live weight of ca. 21 kg to a target weight of 43...

Water quality constituents ingested through drinking water can affect the animal's physiology negatively and, through bioaccumulation in tissues, pose a biohazard to consumers. The study evaluated the effectiveness of a total dissolved solid (TDS) treatment as a possible alleviator of the accumulation of potentially hazardous chemical constituents...

In a 2 x 2 factorial design, attainment of puberty in 32 Black Indigenous (BI) and 60 SA Landrace (SAL) gilts was studied under the effects of two treatment diets fed individually ad libitum. Treatment 1 contained 160 g CP and 13.6 MJ DE/kg DM, and Treatment 2, a 25% dilute of Treatment 1 using wood shavings, contained 120 g CP and 10.2 MJ DE/kg DM...

_______________________________________________________________________________ Abstract Growth and carcass characteristics of three Ethiopian goat breeds, the Afar, Central Highland (CHG) and Long-eared Somali (LES) were evaluated using three grainless diets varying in concentrate:roughage ratios (diet 1 was 50:50, diet 2, 65:35 and diet 3, 80:20)...

This study was undertaken to determine the influence of three grazing pressures [high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the quality of herbage consumed by lambs grazing Lolium perenne and Dactylis glomerata pastures in spring. Feed samples collected via oesophageal fistulae...

This study was undertaken to determine the influence of three grazing pressures [high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the performance of lambs grazing Lolium perenne and Dactylis glomerata pastures in spring. Feed intakes and average daily live weight gains (ADG in g/day)...

The skin and muscle chemical comparisons from normal and golden coloured African sharptooth catfish, Clarias gariepinus, of two different size (± 360 and ± 1500 g live mass) groups are reported. The skin of the golden strain is shown to be that of an albino that contains no melanin. Size has a stronger influence than strain on the proximate, fatty...

The in vitro affinity and adsorption capacity of a humic acid, oxihumate, for aflatoxin B1 (AFB1) was evaluated, utilizing Langmuir and Freundlich adsorption isotherms. Oxihumate showed a high in vitro affinity for AFB1. The Freundlich isotherm fitted the data better than the Langmuir isotherm, and binding capacities of 10.3, 7.4, and 11.9 mg of AF...

This study was undertaken to determine the influence of three grazing pressures [high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the quality of herbage consumed by lambs grazing Lolium perenne and Dactylis glomerata pastures in spring. Feed samples collected via oesophageal fistulae...

Goat meat has been established as lean meat with favourable nutritional quality. Its attributes are concordant with present day consumer demands for leaner and nutritious meat, and hence should be the basis for promoting the meat. Sensory evaluations have shown that goat meat is acceptably palatable and desirable to consumers. The meat may be as ac...

The effects of glycosylation on the stability of an exogenous xylanase exposed to proteases or rumen fluid in vitro, were examined. Commercial xylanase produced by Trichoderma longibrachiatum was purified by gel filtration chromatography, followed by ammonium sulfate precipitation and dialysis. A partially purified xylanase, consisting of proteins...

Recent advances in analytical techniques have allowed hydro-geochemical databases to form an essential component of animal and human epidemiological studies. Geographically localised communities and livestock production systems have a higher incidence of risk factors, and therefore baseline concentrations of key health elements are required to asse...

A 14-day battery trial using 336 four-day old male broilers was undertaken to compare the thermostability and efficacy of phytase produced in solid-substrate culture, a Solid Substrate Enzyme Product (SSEP), with phytase produced in liquid culture, a Liquid Enzyme Product (LEP). Five maize-soyabean meal based diets were formulated; three contained...

Oviposition and egg quality traits were studied in dwarf and naked neck layers in Maputo (Mozambique) during a 28-d period at 35 weeks of age. Birds were caged individually in a laying house with natural light and ventilation. Average daylight length during the study was 11.2 hr and minimum and maximum temperature was 19.6 °C and 30.1 °C, respectiv...

Successful livestock production is dependent on the provision of water with a specific chemical composition. The aim of a WQG is to recommend what the composition should be, not just to prevent adverse effects, but to achieve optimal water utilisation. It is concluded that under the trial conditions experienced in this study, adverse effects due to...

Les races de poules originaires d'Afrique du Sud sont surtout associées à l'habitat rural. Ce n'est qu'en 1994 qu'on a établi un programme de conservation des différentes races d'Afrique du Sud. Comme il n'existait aucunes données scientifiques sur les caractéristiques de production de ces races, on a entrepris des projets de recherches pour les dé...

The productive performance of major genes for feather reduction (naked neck and frizzle) and body size reduction (dwarf) in a dual-purpose layer strain was evaluated in the subtropical coastal region of southeast Africa (Maputo, Mozambique). The experimental material consisted of eight different genetic groups, two diets (14.4 and 16.2% crude prote...

Water samples were collected from 35 boreholes at poultry producers in the Western Cape and were analysed for 43 mineral and trace element constituent inclusion levels. Bicarbonates, chlorides, fluoride, nitrates, phosphates, sodium, cadmium, iron, lanthanum, lead, manganese, mercury, titanium and zirconium were identified as potentially hazardous...

The aim of this study was to determine whether blood metabolite concentrations in free-ranging indigenous goats are sensitive to expected variations in nutrient supply, and whether they could be used to evaluate different kidding seasons at two locations subject to similar seasonal variations in terms of nutrient supply. Monthly blood samples were...

This study was undertaken to investigate the growth performance of calves born to dams with different calving dates and calving intervals. Early calving dams produced calves with the lowest birth weights, the highest actual weaning weights and the highest pre-breeding heifer weights. The higher weaning weights of early calvers were due to higher pr...

One thousand Silver Grey Hyline hens were given drinking water containing 6, 10, 14 and 20 mg/l sodium fluoride during their laying period. The control group received municipal water (containing 0.29 mg/l fluoride) with no added sodium fluoride (0 mg/l). Fluoride addition to the water had a significant effect (P = 0.0001) on egg production, but egg...

The trace mineral status of cattle in the smallholder grazing areas of Sanyati and Chinamhora in Zimbabwe was evaluated during the rainy and dry seasons of 1994 and 1995. The evaluation was done in terms of mineral concentration in blood plasma. Plasma copper in calves, steers and cows in the dry season was; Sanyati: 0.55, 0.59, and 0.61; Chinamhor...

Calving interval is currently used as the measure of reproductive performance in South Africa and many other countries, but some authors have claimed that calving interval is not a suitable measure of reproductive performance, when cows are mated during a restricted breeding season. Numerous authors have suggested that calving date is a suitable al...

1. One thousand Silver Grey Hyline hens were given drinking water containing 5 concentrations of added sodium fluoride (0, 6, 10, 14 and 20 mg/l) over a 17-week growth and 57-week laying period. The natural fluoride content of the water was 0.21 mg/l during the growing period and 0.29 mg/l throughout lay. 2. During the rearing phase, efficiency of...

The validity of the water quality guidelines for livestock watering is questionable as these are based largely on international guidelines and lack locally established water quality constituent lists, levels of acceptability and reference to Southern African livestock production systems. The water quality constituents fluoride, chloride, total diss...

Data consisting of records from 3 040 animals, born of 59 sires and 597 dams, were collected from 1978 to 1991 and analysed to estimate variance components for birth weight, weaning weight, average daily gain (ADG) and Kleiber ratio. Birth year, age of dam, sex and rearing status (a combination of birth and weaning status) were included in the anal...

Faecal samples have been proven to be valuable in determining the nutritional status of wild herbivores. It is often, however, difficult and impractical to collect dung as it is dropped. In this study, the effect of various environmental factors that may influence P and N concentrations in faeces were investigated. Factors examined were rain, age o...

Forty steers of medium maturity were allocated randomly to four treatment groups of 10 steers each (C = Control, βA = β-Agonist, TO = Trenbolone acetate + oestradiol-17β and βTO = β-Agonist in combination with trenbolone acetate + oestradiol-17β). After 56 days on treatment, the β-Agonist treatment was stopped and the steers slaughtered on the nint...

Effects of dietary energy levels and form of diet on the profile and accumulation of fatty acids in subcutaneous adipose tissue of wethers were investigated. Shorn wethers were randomly allocated to a 22 factorially arranged experiment (2 dietary energy levels × 2 dietary presentations × 14 replicates). Two diets were compiled on an isonitrogenous...

The effects of breed and slaughter weight on the profile and accumulation of fatty acids in the subcutaneous adipose tissue of wethers were investigated. Dorper (earlier maturing breed) and SA Mutton Merino (later maturing breed) wethers were randomly allocated to a 22 factorially arranged experiment (2 breeds × 2 slaughter weights × 12 replicates)...

The larval growth potential of four African sharptooth catfish strains over a 56 day growth period was evaluated and found to differ significantly between strains. Strain strongly influenced body total lipid, but not body protein content. Body total lipid content was associated with growth rate. The body amino acid content was not strongly influenc...

The effects of salinomycin (20 mg kg-1 feed), monensin (33 mg kg-1 feed) and a daily rotation of these ionophores, on average daily gain (ADG), average daily feed intake (ADFI) and feed conversion efficiency (FCE) were investigated in 60 steers (273 kg) over an 84-day feedlot period. Individual feed intakes and weight gains were recorded. The data...

Recent ambiguity about the role of animal fat in causing coronary heart disease, coupled with the controversy regarding the effect of various levels of energy nutrition on ruminant depot fats, prompted an investigation into the influence of high-energy nutrition, breed and slaughter weight on the fatty acid profiles of ruminants. Two isonitrogenous...

The anatomical heterogeneity of the African sharptooth catfish, Clarias gariepinus, muscle was investigated in terms of proximate composition, amino acid, lipid fatty acid and muscle mineral concentrations. No distinct differences in the proximate compositions between dorsal and ventral regions were found. There was a decline in moisture and protei...

South African Mutton Merino wethers (n = 32) were slaughtered, yielding carcasses with a mean weight of 22·18 ± 2·11 kg. Sixteen carcasses were electrically stimulated (ES) (21 V, 60 Hz, 120 s) immediately and all carcasses were chilled at room temperature (16°C) for 3 h and then overnight at 4°C, 95% RH. Both left and right Mm. longissimus lumboru...

The fatty acid profiles of the mesenteric fat depot and the lipids extracted from the fillets and the fish diet of farmed African sharptooth catfish, Clarias gariepinus are compared. No statistical differences (p≤0,01) between the fatty acid profiles of the lipids from the fillet and mesenteric fat depot were noted, with the exception of eicosapent...

1. The relative rates of development in a commercial layer and a broiler strain of chicken fed 180 or 230 g crude protein/kg were investigated by the use of the allometric-autoregressive model. Development was divided into pre-pubertal (0 to 8 weeks) and pubertal phases (8 to 22 weeks). 2. Significant strain effects were observed, at all ages, in r...

The effect of continuous administration, weekly 24 h administration, phased withdrawal and phased inclusion of dietary halofuginone at 3 mg kg-1 on skin tensile strength was tested in Ross I broiler pullets. Controls received monensin continuously at 100 mg kg-1. A total of 2,592 birds were used in 2 lots of 1,296 in 2 separate programmes. Continuo...

Halofuginone was administered to both sexes of 2 broiler strains, Ross and Hubbard, in 4 dietary treatments, 0, 1.5, 3 and 6mg kg-1. Controls received dietary monensin at 100 mg kg-1. Group feed intake and body mass were recorded weekly. Skin tensile strength was monitored on Days 28, 35, 42 and 49 using a standardised cut of breast skin from carca...

Afrikaner bulls (n = 30) between 9,5 and 15 months old, were allocated to 2 dietary treatments fed ad libitum. Diet 1 consisted of 70% concentrate and 30% Eragrostis curvula hay (11,4 MJ ME kg-1 DM) and Diet 2 of 40% concentrate and 60% E. curvula hay (9,3 MJ ME kg-1 DM). Five libido tests were conducted per bull between the ages of 16 and 28 month...

The effects of nutrition, breed and sex on the incidence of mortalities and of skin tears on broiler carcasses were studied. Both sexes of 2 breeds, Hubbard and Ross, were given 4 dietary treatments consisting of a normal level of vitamin and mineral premix plus 300 ppm furazolidone, twice normal premix inclusion level plus 300 ppm furazolidone, a...

The levels of eight long chain fatty acids (14:0, 16:0, 16:1 17:0, 17:1, 18:0, 18:1, 18:2) were measured in the subcutaneous fat of S.A. Mutton Merino wethers (5 months old, 20-25 kg live mass, 8 per treatment) and, including 18:3, in eight pastures grazed for 84 days (maize stubble, Z. mays; Triticale; L. multiflorum; L. perenne; D. glomerata; D....

Growth rates of Boer goats were generally lower than sheep and, under favorable nutritional conditions, weight gains of more than 200 g per day were obtained, against values of up to 176 g per day under extensive subtropical conditions. Lactation and pregnancy had a marked effect on ME intake, and the latter had an improved feed conversion ratio (6...

Boer goats evolved in Southern Africa from indigenous African and introduced European stock. Breed standards of the Boer Goat Breeder's Association stipulate color to be white with red head and blaze, pigmented skin and good, functional conformation. Boer goats are hardy, graze a wide spectrum of plants, grasses and shrubs, effectively combating bu...

The proportion of eight fatty acids (14:0, 16:0, 16:1 , 17:0, 17:1,18:0, 18:1 and 18:2) was measured in the subcutaneous and kidney fat depots of five groups of Boer goat castrates which had been kept for 90 days on one of five different diets. The diets were compiled on an iso-N, -Ca and -P basis and varied in their maize and Cenchris ciliaris con...

Goat meat in human nutrition as a primary and supplementary nutrient source is presented in terms of the dist ribution of goats, production characteristics, composition and nutrient value of goat meat, muscle fat and processed goat meat. Man is a complex being living in a complex environment, under varyingdegrees of psychological and physical strai...

The in vitro affinity and adsorption capac- ity of a humic acid, oxihumate, for aflatoxin B1 (AFB1) was evaluated, utilizing Langmuir and Freundlich adsorption isotherms. Oxihumate showed a high in vitro affinity for AFB1. The Freundlich isotherm fitted the data better than the Langmuir isotherm, and binding capacities of 10.3, 7.4, and 11.9 mg of...

Effects of intratesticularly administered zinc tannate (ZT) on growth performance, sexual development, slaughter, carcass and meat quality characteristics of young bull calves (-225 kg, 7 months old) were investigated. Comparisons were made across a three (treatments: ZT animals, intact bulls and burdizzo-castrated steers) by two (slaughter masses:...